dependencies: Fix pkg-config variable definition

In a previous commit variable definition was added in pkg-config.
However, this commit was not complete.

This fixes the missing parts of that commit.

mesonbuild/dependencies/ui.py

@@ -240,7 +240,7 @@ class QtBaseDependency(ExternalDependency):
         self.bindir = self.get_pkgconfig_host_bins(core)
         if not self.bindir:
             # If exec_prefix is not defined, the pkg-config file is broken
-            prefix = core.get_pkgconfig_variable('exec_prefix')
+            prefix = core.get_pkgconfig_variable('exec_prefix', {})
             if prefix:
                 self.bindir = os.path.join(prefix, 'bin')
 
@@ -360,7 +360,7 @@ class Qt4Dependency(QtBaseDependency):
         applications = ['moc', 'uic', 'rcc', 'lupdate', 'lrelease']
         for application in applications:
             try:
-                return os.path.dirname(core.get_pkgconfig_variable('%s_location' % application))
+                return os.path.dirname(core.get_pkgconfig_variable('%s_location' % application, {}))
             except MesonException:
                 pass
 
@@ -370,7 +370,7 @@ class Qt5Dependency(QtBaseDependency):
         QtBaseDependency.__init__(self, 'qt5', env, kwargs)
 
     def get_pkgconfig_host_bins(self, core):
-        return core.get_pkgconfig_variable('host_bins')
+        return core.get_pkgconfig_variable('host_bins', {})
 
 
 # There are three different ways of depending on SDL2:

mesonbuild/modules/gnome.py

@@ -370,7 +370,7 @@ class GnomeModule(ExtensionModule):
                     ldflags.update([lib])
 
                 if isinstance(dep, PkgConfigDependency):
-                    girdir = dep.get_pkgconfig_variable("girdir")
+                    girdir = dep.get_pkgconfig_variable("girdir", {})
                     if girdir:
                         gi_includes.update([girdir])
             elif isinstance(dep, (build.StaticLibrary, build.SharedLibrary)):
@@ -561,7 +561,7 @@ class GnomeModule(ExtensionModule):
                         if subdir not in typelib_includes:
                             typelib_includes.append(subdir)
             elif isinstance(dep, PkgConfigDependency):
-                girdir = dep.get_pkgconfig_variable("girdir")
+                girdir = dep.get_pkgconfig_variable("girdir", {})
                 if girdir and girdir not in typelib_includes:
                     typelib_includes.append(girdir)
         # ldflags will be misinterpreted by gir scanner (showing

run_unittests.py

@@ -1807,8 +1807,8 @@ class LinuxlikeTests(BasePlatformTests):
         self.assertTrue(foo_dep.found())
         self.assertEqual(foo_dep.get_version(), '1.0')
         self.assertIn('-lfoo', foo_dep.get_link_args())
-        self.assertEqual(foo_dep.get_pkgconfig_variable('foo'), 'bar')
-        self.assertPathEqual(foo_dep.get_pkgconfig_variable('datadir'), '/usr/data')
+        self.assertEqual(foo_dep.get_pkgconfig_variable('foo', {}), 'bar')
+        self.assertPathEqual(foo_dep.get_pkgconfig_variable('datadir', {}), '/usr/data')
 
     def test_vala_c_warnings(self):
         '''